1. Field of the Invention
The present invention relates to a multi-layered material and a method for making the same, and more particularly to a multi-layered material having two different foamed structures and a method for making the same.
2. Description of the Related Art
In the manufacturing of various types of balls, a simple ball body is formed entirely by means of direct injection molding a rubber material. A machine sewing or hand sewing process is further developed to create a certain appearance, texture, or comply with specifications dictated by a particular sport. In this process, a bladder needs to be disposed inside the ball body for reason of sewing; air is filled into the bladder during inflation, such that the bladder inflates the ball body, and then a surface cover of the ball is sewn onto the bladder by machine or hand. Conventionally, materials for making the surface cover of the ball include thermoplastic urethane (TPU), polyvinyl chloride (PVC), and polyurethane (PU), which are non-foamed or single-layer foamed.
The conventional surface cover structure of the ball has the following disadvantages. Since the conventional surface cover structure of the ball is rather hard, the hands or feet of players are easily injured due to impact during strenuous sports such as football and volleyball, and the conventional surface cover structure has a poor tactile feel and can make the ball difficult to control. Reinforcement and various other improvements need to be implemented during manufacturing of the ball body, which complicates the manufacturing process and increases the manufacturing cost of the ball body.
Therefore, it is necessary to provide an innovative and inventive multi-layered material and a method for making the same.